Existing transmission systems, whether carrying voice, video or data, have bandwidth limits imposed by domestic and world regulatory agencies controlling the utilization of the frequency spectra. Carrier modulation methods have evolved from the original Amplitude Modulation to present methods combining two or more carriers with Amplitude, Frequency or Phase modulations in various combinations. Advanced carrier modulation methods were developed to maximize energy throughout the assigned channel bandwidth thus providing the greatest available information bandwidth for the assigned communication channel.
A new fundamental carrier modulation was developed and first patented (see, e.g., U.S. Pat. No. 4,613,974 to Vokac et al., incorporated in its entirety herein) that applies a new type of carrier modulation that does not interfere with amplitude, frequency and/or phase modulation coexisting on the same carrier signal.
The concept of Transpositional (TM) Modulation was based on an earlier concept of how to add information to a carrier signal without affecting its amplitude, frequency or phase (see, e.g., U.S. Pat. No. 4,613,974 to Vokac et al., incorporated in its entirety herein). By producing an inflection as shown below, information can be conveyed by the carrier signal. This method is not detected by existing de-modulators of amplitude, frequency or phase modulation.
Using the previously patented method of generation the following time-domain waveform is generated with the inflections exaggerated for clarity. In real-world applications, the inflections are not visible.
A deficiency of earlier methods of generating this type of waveform is a small amplitude variation that required removal by an adjusting circuit. For example, FIG. 1 is an illustration of a TM Modulated signal 100 generated in accordance with the prior art techniques taught by U.S. Pat. No. 4,613,974. As can be seen, an amplitude variation error exists between negative peaks 101 and 102.
Thus, a heretofore unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.